The fast Nikkors of 50mm and wider *all* vignette very obviously wide open and I have and had a handfull (24/2,8, 28/2, 35/2, 50/1,8;1,4;1,2). Use it to your advantage (concentrates the viewers attention to the center together with great swirly bokeh with eg. the 1.2/50mm) or stop down a stop or two.